Platinum Equity focuses primarily on buying non-core assets from major companies. It's complex stuff but the firm has built a strong system to facilitate deals, such as with transition plans, long-term strategies, HR and so on.

And it's paying off. This week Platinum Equity sold PNA Group Holding to Reliance Steel & Aluminum Co. (NYSE: RS) for about $1.1 billion.

Keep in mind that Platinum picked up PNA in 2006 for a cheap $17.5 million. What's more, the firm was able to recap the company and take out a special dividend for $181 million last year.

However, this wasn't just a quick flip. PNA acquired three companies and was able to boost revenues from $1.2 billion in 2005 to $1.6 billion by 2007.

No doubt, it helped that there was a surge in the steel market. But, at the same time, Reliance wants to be aggressive -- and continue to capitalize on the boom. In fact, since 1994, the company has purchased more than 40 companies.

Tom Taulli is the author of various books, including The Complete M&A Handbook and The Edgar Online Guide to Decoding Financial Statements. He also operates MergerBook.com.